Abstracts of Papers Communicated to the Royal Society of London

Abstracts of Papers Communicated to the Royal Society of LondonSource: Proceedings of the Royal Society of London. Series A, Mathematical and PhysicalSciences, Vol. 177, No. 971 (Mar. 18, 1941), pp. S37-S48Published by: The Royal SocietyStable URL: http://www.jstor.org/stable/97478 .

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ABSTRACTS

OF PAPERS COMMUNICATED TO THE ROYAL SOCIETY OF LONDON

In accordance with a resolution of Council, summaries or abstracts of papers are to be published as soon as practicable. The publication of such abstracts in no way indicates that the papers have been accepted for publication in any fuller form. These abstracts are issued for convenience with the " Proceedings of the Royal Society of London" but do not form a part of the "Proceedings".

18 JULY 1940

Melting and crystal structure. By J. W. H. OLDHAM and A. R. UB- BELOHDE. (Communicated by Sir William Bragg, P.R.S.-Received 27 February 1940.)

The role of various types of lattice flaws is discussed in their bearing on melting and crystal structure. Freezing point determinations on lattices of a single molecule indicate the presence of such flaws in the crystals of polymethylene compounds. Freezing point determinations on composite lattices of ketone + paraffin and ketone + ketone emphasize the importance of the rotation of the group for melting, and indicate that lattice holes are easily formed, without marked lowering of the freezing point. Ordered composite lattices are formed when the number of holes does not exceed 12 % of all the methylene groups.

The results emphasize the importance of co-operative effects in lattice flaws. In the equilibrium state of a crystal, such flaws might arise both from energy effects at 00 K, especially in metals, and from energy and entropy effects at higher temperatures. A picture of melting is suggested in which a network of co-operative flaws breaks up the crystal into a mosaic, or aggregate of crystalline micelles, and in which the solid-liquid transition is comparable with a gel-sol transition.

Molecular structure and rubber-like elasticity. By C. W. BUNN. (Com- municated by Sir William Bragg, P.R.S.-Received 16 April 1940.)

The crystal structures of f8 gutta-percha, rubber and polychloroprene have been completely determined by interpretation of X-ray diffraction photographs. The probable molecular structure of oc gutta-percha molecules has also been deduced.

Abstracts [ S 37 ] 8



S 38 Abstracts of Papers

Knowledge of the geometry of these molecules, together with certain features of the crystal structures, lead to a promising theory of the origin of rubber-like properties.

An examination of all the well-established structures of aliphatic molecules has led to the suggestion of a new stereochemical principle which appears to play a large part in determining the bond positions for successions of linked carbon atoms, just as the tetrahedral principle determines the bond positions of any one carbon atom. The principle is also obeyed in molecules containing nitrogen and oxygen atoms as well as carbon. The principle may be used (and has already been so used) to deduce the probable configurations of aliphatic molecules, and is especially valuable for chain polymers.

Potential energy curves in proton transfer reactions. By R. P. BELL and 0. M. LIDWELL. (Communicated by C. N. Hinshelwood, F.R.S.-Received 23 April 1940.)

The potential energy curves involved in proton transfer reactions are discussed, with special reference to the base-catalysed prototropy of ketones. The assumption of covalent binding throughout is inadequate to account in detail for the relations observed between basic strength and catalytic power. Approximate calculations from first principles show that the ionic state may well be of importance in this type of reaction, and the energy curves constructed on this basis give a much more satisfactory picture of the experimental facts.

The distribution of autelectronic emission from single crystal metal points. By M. BENJAMIN and R. 0. JENKINS. (Communicated by R. H. Fowler, F.R.S.-Received 29 April 1940.)

The field emission patterns from metal points show an electron distribution which can be related to the crystal lattice of the metal.

Surface atoms are mobile at relatively low temperature (the actual temperature being dependent on the nature of the metal). Owing to this mobility, the point is able to assume a shape of minimum free energy determined by the surface forces. This shape is the normal equilibrium form at all temperatures in the absence of external forces. It may be a roughly spherical surface with slight flats or hollows.

If an external field is applied, the surface atoms can be made to pile up over various parts of the surface. The degree of surface modification is a function of the strength of the applied field and of the temperature. The surface then is roughly spherical with slight hollows or elevations about 25 atoms in height. The surface can be frozen into any modification by maintaining the field and reducing the point temperature so that mobility ceases.

The flash-over phenomenon in high vacuum is discussed, and an explanation offered.

The effect of small traces of gas is illustrated and it is shown that the gas film is removed at a relatively low temperature 620-670? K.



Abstracts of Papers S 39

The poisoning of a palladium catalyst by carbon monoxide. By M. G. T. BURROWS and W. H. STOCKMAYER. (Communicated by D. L. Chapman, FR.S.-Received 29 April 1940.)

The combination of hydrogen and oxygen on the surface of a palladium catalyst at low partial pressures at the temperature of the laboratory is completely inhibited by very small amounts of carbon monoxide. The poisoning effect is only temporary and, during the induction periods which are observed, the carbon monoxide is removed by the oxygen in the mixture of hydrogen and oxygen. After the induction period combination proceeds at the normal rate. The length of the inert periods observed increases with the amount of carbon monoxide initially added to the system, and the rate of removal of the carbon monoxide increases as its pressure decreases and becomes comparatively very great when the carbon monoxide present does not exceed the amount required to cover the surface of the metal.

The observations recorded can be explained by a development of the hypothesis of de la Rive that the catalysis of the reaction between hydrogen and oxygen and between carbon monoxide and oxygen involves the alternate oxidation of the metal and the reduction of the surface oxide by hydrogen or by carbon monoxide re- spectively.

The reduction of ferric oxalate by isolated chloroplasts. By R. HILL and R. SCARISBRICK. (Communicated by Sir Frederick Hopkins, FR.S.- Received 30 April 1940.)

Two methods have been used to measure the activity of chloroplasts isolated from Stelltaria media, (a) the measurement with haemoglobin of oxygen produced from ferric oxalate, (b) the measurement of the rate of reduction of methaemoglobin in the presence of atmospheric oxygen, the methaemoglobin itself being reduced by the ferrous iron produced. The chloroplasts after isolation show a progressive fall in activity, approaching zero in 3-6 hr. Four different strains of the plant were grown which showed differences in the stability of the chloroplasts after removal. The Qo, measured as rate of oxygen production calculated on the basis of dry weight of leaf is about 20. The Qo, measured as rate of methaemoglobin reduction generally appeared less as the reduction of methaemoglobin by ferrous iron is relatively slow. The reduction of methaemoglobin in presence of ferric potassium oxalate has been studied quantitatively from the point of view of iron, methaemoglobin, and chloroplast concentration. The effect of different light intensities on the reduction of ferric oxalate by chloroplasts is similar to the effect of varying light intensity on photosynthesis in whole plants and lies within the range of values found by different workers. This ferric oxalate reaction is inhibited by urethane. Phenyl urethane inhibits in much smaller concentrations than ethyl urethane. The effective concentrations of urethane are similar to those affecting photosynthesis.




New studies on active nitrogen. I. By LORD RAYLEIGH, F.R.S. (Received 3 May 1940.)

This paper examines quantitatively the behaviour of nitrogen gas emitting the after-glow, under varied conditions.

The integrated light emitted under the most favourable conditions has been measured as 3-18 candle-sec. per c.c. of nitrogen, the (rarefied) nitrogen being reckoned as at N.T.P. The number of quanta emitted is estimated as about 1-3 x 1o-3

of the number of molecules present. It is concluded, in agreement with Kneser, that the addition of unexcited nitrogen

to glowing nitrogen increases the (instantaneous) emission. It was found that a fivefold increase of total pressure produced about a fivefold increase of brightness. These tests were carried out at very low luminous intensities, when the spontaneous decay was negligible during an experiment.

If the active gas contained in 1 1. of weakly glowing nitrogen is allowed to diffuse quickly into an additional 1 1. volume of nitrogen, so as to dilute it by half, the candle power per unit volume is reduced about 4*3-fold. This is a fair approximation with the value 4, which would be expected if the reaction were bimolecular as regards active nitrogen, and is in agreement with the conclusion which has generally been drawn from observation on the rate of decay of the luminosity in closed vessels.

The effect of compressing the glowing gas has been re-examined, using a solid piston moving in a cylinder. It is now found that with the improved arrangements the brightness varies as the inverse cube of the volume. This is the logical conclusion from, and confirmation of, the previous experiments in which the concentration of (1) the inert nitrogen, and (2) the active nitrogen, are separately varied.

A further test was to expand the glowing gas into a doubled volume which was carried out by letting it pass into a supplementary exhausted vessel. This was expected from the previous result to reduce the intensity 8 times, but in fact did not reduce it more than 7 times. The gas was therefore somewhat brighter after the expansion than had been expected. Most sources of error would have the opposite effect, and there is an outstanding discrepancy in this result.

The effect of temperature on the nitrogen after-glow is examined quantitatively, maintaining the cooler and hotter portions in pressure equilibrium. Cooling to liquid air temperature, for instance, increases the brightness some 80 times. Most, but not all, of this is due to the additional concentration. Assuming (in accordance with the compression experiment) that the brightness is as the cube of the concentration, and correcting the results to uniform concentration, it is found that over the range examined the brightness varies as T-0 64 when T is the absolute temperature.

The positive temperature effect on ordinary chemical reaction corresponds to something more like T+100.

New studies on active nitrogen. II. By LORD RAYLEIGH, F.R.S. (Received 3 May 1940.)

It is shown that pieces of sheet gold, copper, silver, or platinum may be made red hot or even melted by exposing them to active nitrogen produced in a low pressure discharge. The nitrogen gives up its energy to the metal, which remains unacted on.




This phenomenon is applied to measuring the energy of active nitrogen, drawing a known quantity of gas through the activating discharge and then over the metal, and measuring the energy liberated on the latter.

The amount of energy collected from the gas was surprisingly large, and is difficult to reconcile with existing theories of the nature of active nitrogen. In some cases the energy was as high as 10 eV for every molecule of nitrogen that passed through the discharge. This quantity of energy can with difficulty be accounted for by dissociation, even if it occurred to the extent of 100 %. The energy radiated as after-glow under favourable conditions is only of the order of 10-3 of the energy collected by the metal.

Two-phase equilibrium in binary and ternary systems. II. The system methane-methylene. III. The system methane-ethane-ethylene. By M. GUTER, D. M. NEWITT and M. RUHEMANN. (Communicated by A. C. C. Egerton, Sec.R.S.-Received 6 May 1940.)

The liquid-vapour equilibrium of the system methane-ethylene has been determined at five temperatures between 0 and - 1040 C and over a wide range of pressures. The results are shown on pressure-composition curves and by a three dimensional pressure-temperature-composition diagram. The equilibrium of the ternary system methane-ethane-ethylene has also been determined at 0, -78 and - 1040 C. The relation between the phase behaviour of the two binary systems methane-ethylene and methane-ethane and that of the ternary system is discussed and illustrated by a pressure-composition diagram covering the pressure range 10-35 atm. and the whole range of compositions.

Investigations on the vibration spectra of certain condensed gases at the temperature of liquid nitrogen. By G. K. T. CONN, E. LEE, G. B. B. M. SUTHERLAND and C. K. Wu. (Communicated by R. G. W Norrish, F.R.S.- Received 10 May 1940.)

A description is given of experimental methods which have been developed for the investigation of infra-red and of Raman spectra at the temperature of liquid nitrogen. The infra-red spectrometer is essentially the Pfund-Barnes type but it has been found possible to dispense with the fore-prism and to separate the over- lapping orders from the grating by means of filter shutters. The spectrometer is used as a monochromator so that radiation only enters the absorption cell after it has been through the diffraction train. The absorption cell has been designed so that it may be used for high as well as low temperatures. The apparatus for the Raman effect is a modification of that introduced by De Hemptinne, being especially suitable for the examination of small quantities of material.




The infra-red and Raman spectra of hydrochloric and of deuterochloric acids at liquid nitrogen temperatures. By E. LEE, G. B. B. M. SUTHERLAND

and C. K. Wu. (Communicated by R. G. W. Norrish, F.R.S.-Received 10 May 1940.)

The infra-red absorption spectrum of solid hydrochloric acid has been obtained at the temperature of liquid nitrogen (i.e. approximately twenty degrees below its transition point) in the region of the fundamental frequency. The results obtained agree in general with the earlier observations of Hettner and disagree with those of Shearin who reported discrete rotation lines. The doublet band observed by Hettner has been resolved into two separate bands with maxima at 2701 and 2744 cm.-' and indications of a third band were obtained. Some fine structure, very different from that reported by Shearin, was observed on each of the two bands, which were unsymmetrical in shape, being steeper on the low frequency side. The Raman spectrum was obtained at the same temperature and also showed a doublet structure in contrast to earlier observations at higher temperatures which had given only a single line. The maxima of the two Raman lines lay at 2709 and 2759 cm.-'. The explanation of this doubling is to be sought in the manner in which the hydrochloric acid molecules associate in the solid state, since the alteration in the fundamental frequency from that found in the gaseous state shows that strong interaction must exist. The absorption due to the fundamental frequency of deuterochloric acid was observed under the same conditions. Here three maxima were observed at 1965, 1982 and 1992 cm.-' and indications of more structure. These results show that the association of HC1 and DCI molecules in the crystal below the transition temperature can probably take place in several different ways. Such a conclusion is in agreement with the X-ray investigations which revealed a symmetry so low that the crystalline structure could not be determined.

The kinetics of mutarotation in solution. By J. C. KENDREW and E. A. MOELWYN-HUGHES. (Communicated by R. G. W. Norrish, F.R.S. Received 14 May 1940.)

The kinetics of the mutarotation of representative reducing sugars from the pentose, hexose and disaccharide series have been investigated polarimetrically over wide temperature ranges in aqueous solution.

The dependence of the velocity coefficient, k, upon temperature, T, is fairly well reproduced by an equation of the form

ln k = C+ (J/R) ln T-E/RT.

E, the energy of activation at the absolute zero, is found to be some 6000 cal. greater than the apparent value afforded by the Arrhenius equation at room temperature. J/R has a value of - 10, which is identified as the number of oscillators contributing to the activation.

The constants C, J and E of this equation are discussed, with reference to various reactions, in terms of a theory of unimolecular reactions in solution.




Foraminifera from the Green Ammonite Beds, Lower Lias, of Dorset. By W. A. MACFADYEN. (Communicated by W D. Lang, F.R.S.-Received 14 May 1940.)

This paper is a contribution to the long continued researches on the Dorset Lias by W. D. Lang, F.R.S., who collected the described material.

Some 700 mounted specimens from the Lower Lias (davoei zone), of the Dorset coast have been studied. They are ascribed to six families, twenty genera, and fifty-five species; of these, eleven genera and forty-five species belong to the family Lagenidae. One genus and species, Carixia langi, and one other species, Lagena davoei, are described as new, and two new names are proposed to replace invalid names.

There were studied for comparison certain of the few described English Lias faunas, some described French and German material, and a number of well preserved but undescribed faunas from various Lias horizons and different English localities. This has yielded provisional evidence of the zonal ranges of the Dorset species. Some forms of Frondicularia were found to provide useful horizon markers.

A tentative correlation is given of the zoning of the Lias by various authors of papers on Lias Foraminifera; there are notes on the horizons of some described Lias faunas, and a review of previous work on British Lias Foraminifera.

Study of Jurassic Foraminifera has been comparatively neglected for many years, though there is a recent German revival. Some lengthy synonymies are therefore necessary. Certain ill-known forms are discussed in detail; they were inadequately described and figured, so that they have hitherto been wrongly placed. It has thus been possible to rectify the systematic position or status of the genera Involutina, Problematina, and Bullopora. The appearance in the Lias of Bolivina and Plecto- frondicularia is demonstrated, genera usually stated not to occur in rocks of age earlier than the Cretaceous.

Foraminifera thrived in some of the Lias clays in which their shells are well preserved. There was a rapid evolution of new types, particularly of the predominating Lagenidae. In this family there appears to be wide variation within some of the groups, where neither "species" nor even "genera" are sharply defined.

The bulk of the paper is taken up by the systematic description of the Foraminiferal fauna; all the recorded forms are figured.

Inner excited states of the proton and neutron. By W. HEITLER and S. T. MA. (Communicated by N. F. Mott, F.R.S.-Received 14 May 1940.)

The present meson theory exhibits a number of serious difficulties if applied to the interaction of fast mesons with nuclear particles. In order to avoid these difficulties the following hypothesis is made: Charge and spin of a proton and neutron shall be capable of assuming higher quantum states. Thus particles shall exist with approximately protonic mass and with charges + 2e, - e, etc., and also with spins 3/2, 5/2.... It is assumed that the lowest of these higher states have excitation energies which turn out to be of the order of magnitude of 20 MeV. The higher spin states are introduced in the way of a simple model, namely that of a rotator with half-integer



S 44 Ab8tract8 of Papers

angular momentum. The theory is essentially non-relativistic with respect to the heavy particle.

The theory leads to the following results: (i) The cross-section for scattering of mesons by a heavy particle is smaller by

an order of magnitude than according to the former theory (and in qualitative agreement with experiments) and does no longer increase with energy. Thus no multiple showers are to be expected in this theory.

(ii) The anomalous magnetic moments of the proton and neutron diverge only logarithmically and, if the theory is limited to energies smaller than the rest energy of the proton, are in reasonable agreement with the experimental values.

(iii) The influence of the higher states on the nuclear potentials results in a deepening of the potentials at small distances. Even without introducing neutral mesons there is strong attractive proton-proton potential and it is discussed whether the proton-proton scattering data can be explained without this hypothetical particle.

(iv) The deviation from the Coulomb law for a proton derived from the former meson theory is much smaller in the new theory, whereas for the photo-disintegration of the deuteron the characteristic meson effects are expected to be even more marked.

The possibilities for observing the new particles are discussed. It is pointed out that it would have been unlikely had the particles been discovered in any of the experiments which have been carried out up to the present. Yet, one track published by Anderson and Neddermeyer, which cannot be due to any of the known particles, is tentatively interpreted as due to a particle with charge 2e and protonic mass.

Succinic dehydrogenase-cytochrome system of cells. Intracellular respiratory system catalysing aerobic oxidation of succinic acid. By D. KEILIN, F.R.S. and E. F. HARTREE. (Received 17 May 1940.)

The succinic dehydrogenase-cytochrome system, even in the cell-free colloidal pre- paration, behaves like a true respiratory system of the cell, showing the high catalytic activity and being affected by all the inhibitors in the same way and to the same degree as the respiration of intact cells. The efficiency of this system depends not only on the integrity of all its components but also on that of the colloidal structure which supports them and assures their mutual accessibility. The paper deals with the properties of each of the components of the system and with the mechanism of their interactions.

Bose-Einstein statistics and degeneracy. By D. S. KOTHARI and B. N. SINGH. (Communicated by M. N. Saha, F.R.S.-Received 17 May 1940.)

The thermodynamic properties of degenerate and non-degenerate Bose-Einstein gas in the completely non-relativistic and the completely relativistic cases are derived. The relativistic degenerate case of Bose-Einstein statistics corresponds to black-body radiation. The properties and the possibility of the existence of non- degenerate radiation are discussed.




A study of sensitized explosions. V. Some new experiments on the hydrogen-oxygen reaction sensitized by nitrogen peroxide. By F. S. DAINTON and R. G. W. NORRISH, F.R.S. (Received 21 May 1940.)

The effect of pressure and temperature of reactants, of inert gases, of vessel diameter and of surface condition on the induction periods and explosion boundary of 2H2 +02 mixtures containing nitrogen peroxide have been determined in the temperature range 250-410? C. The principal results may be summarized:

(a) Increase of pressure causes the separation of the upper and lower limiting concentration of sensitizer to increase from zero, to a maximum value at the inversion pressure. Above this pressure the upper limit decreases and the lower limit increases linearly with increase of pressure. The induction periods of H2-02-NO2 mixtures of constant NO2 content decrease rapidly with increase of pressure, approaching a small value asymtotically.

(b) All foreign gases lengthen the induction periods and eventually quench the ignition of an explosive mixture of H2-02-NO2 of constant composition. The order of efficiency of the non-reactant gases in lengthening the induction periods is CO2 > N2 > A = He, whereas the order of efficiency in quenching ignition is

C02>He>N2>A.

(c) The induction period at the upper limit always exceeds the induction period at the lower limit. The reverse is true of the rates of the slow reactions in the vicinity of the limits.

(d) At constant total pressure rise of temperature causes the upper limit (Ps,) to be raised according to the equation

log Pu = E/RT + a constant.

E is 19,500 cal. at a total pressure of 75 mm. and increases with pressure to 25,600 cal. at 472 mm.

(e) At constant pressure the upper limit decreases and the lower limit increases as the reciprocal of the square of the diameter.

A study of sensitized explosions. VI. Experimental observations on the hydrogen-oxygen reaction sensitized by nitrosyl chloride. By F. S. DAINTON and R. G. W. NORRISH, F.R.S. (Received 21 May 1940.)

Small amounts of nitrosyl chloride lower the ignition temperature of 2H2 + O. mixtures by over 2000 C; the efficiency in this respect of this substance being slightly greater than nitrogen peroxide. At a given temperature the ignition is confined between a lower and an upper concentration of catalyst, outside which only slow reaction occurs. Both the slow reaction and the ignition are preceded by an induction period, the length of which passes from large values through a minimum to further large values as the catalyst concentration is increased, and which, in contrast to the H2-02-NO2 system, is unaffected by irradiation with light from a mercury vapour lamp.




The induction periods and limits depend on the pressure and temperature of reactants in a very similar way to the induction periods and limits of the H2-02-NO2 system described in V. The similarity of the two systems extends to the effect of non-reactant gases in quenching the ignition: the quenching pressures being of the same magnitude in both systems. A difference is, however, found in that these foreign gases shorten the induction period in this system whereas they lengthen it in the H12-02-NO2 system.

A study of sensitized explosions. VII. A chain-thermal theory of the reaction between hydrogen and oxygen sensitized by nitrogen peroxide or nitrosyl chloride. By F. S. DAINTON and R. G. W. NORRISH, F.R.S. (Received 21 May 1940.)

Both these reactions are chain processes for which the net branching factor 5b is inversely proportional to the induction period. By applying this relation to the experimental results described in V and VI, it is shown that ignition only occurs when the net branching factor attains a value determined by the sum of two quantities, one proportional to the thermal capacity and the other proportional to the thermal conductivity. It is pointed out that this ignition condition cannot be accounted for by any isothermal theory of ignition, but that it may readily be deduced from a thermal theory in which explosion is visualized as occurring only when the initial reaction rate, in a favourable volume element, is large enough to ensure that a critical temperature TC is reached in a critical time t,.

Theories of reaction kinetics are developed from these two systems which give q in terms of the experimental variables. The expressions so deduced lead to a dependence of the induction period on these variables identical with that found experimentally. The effects of vessel diameter, surface condition, temperature, and concentrations of sensitizer, reactants and foreign gases on the explosion are satis- factorily accounted for by substituting these expressions in the ignition condition of the chain thermal theory.

X-ray studies of the molecular structure of myosin. By W. T. ASTBURY, F.R.S., and S. DICKINSON. (Received 23 May 1940.)

Starting from the similarity between the X-ray diffraction patterns of muscle and myosin and those of mammalian keratin fibres, a detailed X-ray and elastic study has been carried out of strips of myosin film prepared by drying the sol.

Methods are described of orienting the myosin chain-molecules: when oriented but unstretched they are found to give an a-photograph almost indistinguishable from that of unstretched keratin, and when stretched a fl-photograph almost indistinguishable from that of stretched keratin. As with keratin, the long-range elasticity rests on a reversible intramolecular transformation, the fully extended, or f-, form of the molecule being again about twice as long as the folded, or az-, form.




The X-ray and elastic properties of myosin are found to resemble most closely, not those of natural keratin, but those of keratin that has suffered breakdown among the cross-linkages (including disulphide bridges) of the polypeptide grid. For example, by pressing moist myosin at ordinary temperatures selective orientation is brought about analogous to what is produced in keratin only at higher temperatures. Similarly, myosin supercontracts in hot water or cold dilute alkali without the preliminary stretching treatment required by keratin.

The supercontraction of myosin has been studied quantitatively and the accom- panying structural changes followed by X-rays. The results show that the effect cannot be explained as due simply to disorientation of long thin units: it must involve a further folding of the polypeptide chain system.

The hypothesis is put forward that the contraction of muscle arises from supercontraction of its myosin component. It will be shown in a subsequent paper that X-ray photographs of muscle in various states, both living and dead, are entirely consistent with this view.

The fact that myosin and keratin are similar in both molecular configuration and elastic properties is discussed in the light of recent X-ray and chemical findings, and the X-ray interpretation is given of the denaturation of myosin.

Anomalous viscosity. By A. S. C. LAWRENCE and J. R. ROBINSON. (Communicated by E. K. Rideal, F.R.S.-Received 25 May 1940.)

Anomalous viscosity is examined from first principles. A viscometer is described for the simultaneous measurement of viscosity and streaming birefringence; the latter property is used to give direct evidence of the nature of the orientation associated with the measured value of the viscosity under the same flow conditions. A number of sols have been examined and the results confirm the analysis. Predicted temperature effects have been confirmed. The effects of particle size, shape and concentration are considered with special reference to the conditions needed to obtain results which can be interpreted. Several related phenomena also receive explanations.

The colours of the plumose anemone Metridium senile (L.). By D. L. Fox and C. F. A. PANTIN, F.R.S. (Received 30 May 1940.)

The anemone Metridium senile occurs in a number of striking colour varieties. These are to be found side by side in nature. The colours are inherited at least during asexual reproduction and do not depend on special food. The colour varieties are founded on three systems of pigment, black granular melanin in the endoderm, brown diffuse melanin in the ectoderm and red to orange lipochrome in fat droplets in both endoderm and ectoderm. In any variety each system may be present or absent. If all are absent we have a white form, if one is present we get red, brown or grey forms, if two or more are present we get other varieties. In combinations each pigment retains the distribution it has in the corresponding simple form.

The black endodermal pigment is a true melanin. The brown ectodermal pigment is also a melanin but is less stable. Even the white variety can be shown to possess




a complete tyrosinase system when the tissues are finely ground. It is perhaps comparable to a case of dominant albinism.

The red and orange colours are due to a variety of lipochromes. The pigment of the red variety is chiefly the acidic carotenoid described by Heilbron, Jackson and Jones. It is related to astacene and we have named it "metridene". Yellow-orange anemones of the red series may contain considerable quantities of xanthophylls in addition to metridene esters. The only pigment of the white form is contained in the gonads and appears to be astacene.

Many of the carotenoids are present in too small quantities to influence the appearance of the animal. The assortment of carotenoids present varies considerably from one lot of Metridium to another. There is evidence that the occurrence of a variety of xanthophylls and carotene is more common in varieties which develop melanin. But there is no obvious correlation between the presence of a particular assortment of carotenoids and a particular distribution of melanin pigments. Flavines are not present in any of the colour varieties.

Coloured purine compounds are not present. The presence of significant quantities of uric acid was demonstrated and of this purine alone. It is present in the mesenteric filaments, in the yellowish excreted mucus, and granules of uric acid form white bands in the endodernn of the tentacles. In this position they contribute their whiteness to the total colour effect. Haematins do not contribute to the colour. Those that are present are derived from the ordinary intracellular respiratory systems.

The colours of the varieties are not an adaptation to the external environment as in warning coloration, etc., nor is there evidence as yet that the colour as such is of direct physiological importance to the animal. The varieties appear to illustrate Poulton's category of "non-significant colours ", in which colour is a by-product of biochemical processes utilized for other purposes.

fl-ray spectra of light elements. By A. A. TOWNSEND. (Communicated by J. D. Cockeroft, F.R.S.-Received 30 June 1940.)

A magnetic spectrometer has been used to investigate the fl-ray spectra of some elements of low atomic number. It is found that all the spectra follow the Fermi distribution law for a certain range from the high energy end-point; the range over which this is true is much greater if the maximum energy is large. The end-points found are: C" 0 981 + 0.005 MeV, N13 1 218 + 0 004 MeV, Mn56 2 88 ? 0 01 and 1*035 + 0*015 MeV, Cu64 (positrons) 0-649 + 0*004 MeV, Cu64 (negatrons) 0 574 + 0 004 MeV, Zn63 2-320 + 0 005 MeV.

X-ray electrons expelled from metals by silver Ka1 radiations. By C. J. BIRKETT CLEWS and H. R. ROBINSON, F.R.S. (Received 3 June 1940.)

The energies of the X-ray electrons expelled frorn targets of gold, platinum, silvei and copper by silver Ka,. rays have been measured in the magnetic spectrograph. The results have been combined with those of earlier measurements, and they yield a value for Planck's constant of 6-629 x 10-27 erg sec.



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